The eye is the most commonly used (and un-refuted) example of a bad design in humans. Our eye flips the image upside-down, sends it to the brain, which then has to flip it back the other way in order to process it. This does not show "design", it shows incompetence...or "Evolution".
Another few bad designs (in humans anyway) include the oesophagus, which allows both air and food / water down. The problem with this is that food can get accidentally sent down the "wrong tube" and into the lungs, causing choking. Many evolutionary biologists have come up with "improvements" on this system, ranging from having separate tubes, to having a single tube but repositioning the entry to the lungs. Either way, we seem to have out-designed our "designer".
Another few bad designs (in humans anyway) include the oesophagus, which allows both air and food / water down. The problem with this is that food can get accidentally sent down the "wrong tube" and into the lungs, causing choking. Many evolutionary biologists have come up with "improvements" on this system, ranging from having separate tubes, to having a single tube but repositioning the entry to the lungs. Either way, we seem to have out-designed our "designer".
